Hinge seat cutting tool



Dec. 18, 1962 A. M. SUNDBY 3,063,917

HINGE SEAT CUTTING TOOL Filed April 5, 1961 2 Sheets-Sheet 1 V FIG FIG. 2

FIG. 3

INVENTOR ARTHUR M. SUNDBY ATTORNEY Dec. 18, 1962 A. M. SUNDBY 3,068,917

HINGESEAT CUTTING TOOL Filed April 5, 1961 2 Sheets-Sheet 2 v FIG. 5

INVENTOR ARTHUR M. SUNDBY ATTORNEY United. States Patent 3,068,917 HINGE SEAT CUTTING TOOL Arthur M. Sundby, 1915 14th Ave. S.,

- Minneapolis, Minn. Filed Apr. 5, 1961, Ser. No. 100,952 3 Claims. (Cl. 144-27) This invention relates broadly to powered hand tools, more particularly to a novel portable electric sabre saw, and specifically to an electric sabre saw which will simultaneously cut the hinge seats in a door and the door jamb when said door is positioned in the door frame.

The principal object of this invention is to provide an electric sabre type saw that will simultaneously make the hinge seat cuts in the door and the door jamb for standard double leaf hinges.

A further object of this invention is to provide an electric hinge seat cutting tool wherein said tool, when positioned for cutting said seats will provide the required clearance between the door and its frame when said door and frame are in assembled relation.

A still further object of this invention is to provide an electric hinge seat cutting tool that is capable of producing hinge seats for standard double leaf hinges of various sizes.

These and other objects of the invention will become apparent from the following specification and claims when taken in conjunction with the accompanying drawing which forms a part of this application and in which draw ings, like characters indicate like parts throughout the several views. i i

Tothe above end, generally stated, the invention consists of the following devices and combinationof devices hereinafter described and defined in the claims.

Referring to the drawings:

FIG. 1 is a top plan view of the invention in operable position on a door.

FIG. 2 is a side elevational view of the same.

FIG. 3 is an end elevational view with some parts broken away, taken on the line 33 of FIG. 1.

FIG. 4 is a side elevational view of the invention on an elevational view of the invention on an enlarged scale, some parts thereof being broken away taken on the line 4-4 of FIG. 1, and

FIG. 5 is a fragmentary top plan viewof the saw mounting some parts being broken away and sectioned on the line 5-5- of FIG. 4.

Referring in detail to the drawings, the numeral 6 is directed to a rectangular mounting plate having a pair of downturned flanges 7 along its right hand edge portion to thus provide an integral clearance gauge between the edge of the door 8 and the door jamb 9 in which the hinge seat cuts are made simultaneously.

At this point it is well that it be understood that the door is positioned and wedged against the jamb 9 with the flanges 7 affording clearance and the depth of the hinge cut governed by the predetermined thickness of the saw blade as will presently appear. It is only necessary to slide the mounting plate 6 and its mounted components along the edge of the door *8 to the proper position for the cutting of the upper and lower hinge seats and any intermediate seats that may be required. Mounted on the mounting plate 6 are a pair of transversely spaced longitudinally disposed rails 10 and an adjustable stop member 11, the purpose of each of these will presently appear in detail.

A base plate 12 is constructed and arranged to run on the rails 10 by means of a pair of inter-locking rails 13 secured to the underside of the base plate 12 in register with the pair of rails 10 to provide for longitudinal movements of the base plate 12 relative to the mounting plate 6.

An electric motor 14, having a double armature shaft 3,068,917 Patented Dec. 18, 1962 extension 15, a manipulating handle 16 and a switch 16', is mounted transversely of the rails 10 and 13 between right and left hand pillow blocks 17 and 18, respectively, that are secured rigidly to the base plate 12 by studs 19. Bearings 20 are mounted in the pillow blocks 17 and 18 and the armature shaft extension 15 are journaled in said bearings 20.

The right hand pillow block 17 comprises a fixed peripheral ring 21 having a base 21 that is secured to the base plate 12 by the studs 19 and a movable bearing 22, said bearing 22 being journaled in the fixed ring 21 with a close working fit as indicated by the numeral 23 and is held rigidly secured to the electric motor 14 for rotating movement therewith by studs 24 that extend through the movable bearing 22 into screw threaded engagement with the housing of said electric motor 14. It will be understood that the righthand extension of the armature shaft 15 is journaled in the movable bearing 22 of the pillow block 17 and terminates outwardly thereof, see FIG. 5, for a purpose that will presently appear. A spacer Washer 25 is interposed between the end portion of the housing of the electric motor 14 and the inner face of the movable bearing 22 of the right hand pillow block. 17 to permit the free axial rotation of the motor 14 and the connected movable bearing 22 of said pillow block by thus affording clearance between said elements and the fixed portion 21 of the pillow block 17 and a part of the end portion of the housing of the motor 14.

The movable bearing 22 of the right hand pillow block 17 is held in predetermined fixed position relative to the fixed ring 21 by the engagement ofa spring loaded plunger 26 formed in an outstanding lug 26 in the periphery of the movable bearing 22 in the right hand pillow block 17 and a plurality of bores 27 in the marginal outer edge portion of the fixed ring 21. These bores 27 are spaced at one to the other and as shown, there are three such positions affording three fixed positions of the motor 14 and its mounted components relative to the fixed ring 21 wherein the spring loaded plunger 26 is normally in engagement with one of the bores 27. In the two horizontally disposed positions the unit is inoperable as will presently be seen, and in the single vertical position, the unit is operable.

A screw-threaded stud 28 is formed in the outer end portion of the right hand extension of the armature shaft 15 and an eccentric circular cam 29 has threaded engagement therewith. This eccentric circular cam 29 has working engagement, see FIG. 4, with a substantially square yoke 30 that operates with reciprocating motion in a yoke housing 31 that is rigidly secured to the movable bearing 22 of the pillow block 17 by means of screw threaded studs 32. The eccentric circular cam 29 has close fitting engagement at two diametrically opposite points with the interior surfaces of the square yoke 30 and the said yoke has free floating, close fitting engagement with the interior of the yokehousing 31. A relatively stiff and crosssectionally thick two edged saw blade 33 is mounted on the yoke 30 by means of screw threaded studs 34. The outer end portion of the saw blade 33 extends outwardly of the yoke housing 31 through a narrow slot 35 in said housing and has a close working fit therewith to afford additional support and guide means for the said saw blade during its reciprocating movements induced by the action of the eccentric circular cam 29.

In a normal operation of simultaneously cutting ofi said hinge seats in a positioned door 8 and the door jamb 9, the mounting plate 6 is applied to the door 8 with the flange 7 forming a spacer between the said door and the jamb. It will be assumed that the electric motor 14 is connected to a power source, not shown, and the said motor energized by closing the switch 16. The yoke and cam and saw assembly is thus activated into reciprocating motion. The spring loaded plunger 26 is withdrawn from one of its horizontal locking positions and the motor 14 and its mounted components, the movable bearing 22, the cam 29, the yoke assembly 30 and 31 and the saw blade 33, is swung about the axis of the armature shaft 15 of the motor 14 until the saw blade 33 is brought into contact with the wood of the door 8 and the door jamb 9. Actually, one side of said saw blade 33 will cut the hinge seat in the door while the other side thereof will cut the hinge seat in the jamb while the cross-sectional center of the saw 33 will travel freely in the clearance between these two elements of wood. It will thus be clear that the purpose of providing a saw blade 33 that is relatively thick in cross-section is to provide the necessary depth for the cut without any lateral adjustment of the blade 33.

As the blade 33 engages the wood the operator continues to force the same through the arc of a circle until the said blade is in a vertical position and working in its initial semi-circular out. With the blade 33 in this vertical position the spring loaded plunger 26 is moved into engagement with the top or vertically disposed bore 27 in the fixed ring 21 to thus hold the assembly locked with the said saw blade in a vertical position. With the assembly so locked and positioned, the base plate 12 is moved forwardly and rearwardly on the rails and 13 Within predetermined limits, to form the rectangular hinge seat simultaneously in the door 8 and the jamb 9. Obviously the unit is released from the saw cut hinge seats by the reverse procedure of withdrawing the spring loaded plunger 26 from the top or vertical bore 27 and then rotating the motor, cam and saw assembly about the longitudinal axis of the motor 14 until the saw blade 33 is in a horizontal plane.

While there are herein disclosed but a limited number of embodiments of the structure, process and product of the invention herein presented, it is possible to produce still other embodiments without departing from the inventive concept herein disclosed, and it is desired, therefore, that only such limitations be imposed on the appended claims and are stated herein or required by the prior art.

What I claim is:

1. A powered hand tool for simultaneously cutting the hinge seats in a door and a door jamb, comprising in combination a relatively thin rectangular mounting plate, a pair of laterally spaced guide rails mounted on said mounting plate, a base plate having a pair of laterally spaced guide rails mounted on the underside thereof and having interlocking engagement with the first noted guide rails on the mounting plate whereby said base plate is mounted on the said mounting plate for limited endwise movements relative thereto, a downturned flange formed in the right hand edge portion of the mounting plate atfording spacer means between the door and the door jamb, an electric motor journaled in a pair of pillow blocks mounted in lateral spaced relation on the said base plate, said electric motor having a double extension armature shaft said extension being journaled in bearings mounted in said pillow blocks, an eccentric circular cam mounted on the outer end portion of one of the armature shaft extensions, a movable bearing journaled in the right hand pillow block said bearing being rigidly secured to the electric motor for rotation therewith about the longitudinal axis of said motor, said movable bearing having selective interlocking engagement with the said right hand pillow block, a housing mounted on the outer edge portion of the movable bearing and a yoke, cooperating with the cam, mounted in said housing for reciprocating movements, and a cutting blade rigidly secured to the yoke and extending outwardly of the said housing for work engagement.

2. The structure defined in claim 1 wherein said selective interlocking engagement comprises a plurality of bores in the right hand pillow block and a spring loaded plunger mounted in the movable bearing in circumferential register with said bores whereby saidmovable bearing and its mounted cam and cutting means are adjustable to a plurality of locked positions relative to the said pillow block.

3. A powered hand tool for simultaneously cutting the hinge seats in a door and a door jamb, comprising in combination, a relatively thin rectangular mounting plate having a downturned flange formed in its right hand edge portion, a pair of laterally spaced guide rails mounted thereon, a relatively thin base plate having a pair of guide rails mounted on the underside thereof said last noted guide rails having interlocking engagement with the first noted guide rails on the said mounting plate whereby the said base plate is end-wise movable relative to the said mounting plate, and stop means on the mounting plate whereby said movement of the base plate relative thereto is selectively limited, an electric motor having a housing, journaled in the bearings mouted in a pair of pillow blocks rigidly secured to the base plate, said electric motor having a double extension of its armature shaft whereby said motor is mounted in the bearings in the pillow blocks for manual rotation of the said motor about the axis of its armature shaft, an eccentric circular cam mounted on the outer end of the right hand extension of the armature shaft of the electric motor, a movable bearing journaled in the right hand pillow block and rigidly secured to the electric motor for rotation therewith, a housing secured to the outer edge portion of the said movable bearing and a yoke mounted in said housing and having a close working fit therewith, said cam operating in said yoke to impart reciprocating movements thereto and a relatively heavy double edged saw blade mounted on the said yoke for movement therewith, said saw extending outwardly of the housing for engagement with its work.

References Cited in the file of this patent UNITED STATES PATENTS 1,865,576 Luginbuhl July 5, 1932 2,627,882 Kleinsmith Feb. 10, 1953 2,656,860 Thayer Oct. 27, 1953 2,785,712 Person Mar. 19, 1957 2,822,833 Mondrick Feb. 11, 1958 2,868,248 Pedersen Jan. 13, 1959 2,960,124 Sundby Nov. 15, 1960 

